There are two major cerebral oxidative pathways by which glucose can be metabolized to supply energy requirements. It is our intention to determine the absolute and relative activities via each mechanism under basal conditions and under anesthesia of graded depth. Each of the commonly used types of volatile anesthetic agents will be examined. This would provide insight into the molecular effects of anesthesia, and might furnish clinical guides (e.g., glucose infusion for increased dependence upon the pentose pathway).